Wiess, AJ & Elixhauser A (October 2014). "Overview of Hospital Utilization, 2012". HCUP Statistical Brief (180). Rockville, MD: Agency for Healthcare Research and Quality. Archived from the original on 2014-12-24. Retrieved 2014-10-20.
Wiess, AJ & Elixhauser A (October 2014). "Overview of Hospital Utilization, 2012". HCUP Statistical Brief (180). Rockville, MD: Agency for Healthcare Research and Quality. Archived from the original on 2014-12-24. Retrieved 2014-10-20.